<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>计数器</title>
		<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
	</head>
	<body>
		<div id="app">
			<div class="input-num">
				<button type="button" @click="sub">-</button>
				<span>{{ num }}</span>
				<button type="button" @click="add">+</button>
			</div>
			
		</div>
		
		<script type="text/javascript">
			var app = new Vue({
				el: "#app",
				data:{
					num: 2,
				},
				methods:{
					add:function(){
						console.log("add");
						if(this.num < 10){
							this.num ++;
						}else{
							alert("已加最大了");
						}
					},
					sub:function(){
						console.log("sub")
						if(this.num>0){
							this.num --;
						}else{
							alert("已经最小了")
						}
					}
					
					
				},
				
				
			})
		</script>
		
	</body>
</html>
